The raw sewage discharged from the human body is typically discharged to a sewage system by use of a flush toilet in an ordinary house or is discharged into a river after being temporarily stored in a holding tank and purified therein. However, at events such as festivals, athletic events, fairs and the like, temporary toilet facilities must be provided.
Employed conventionally are movable temporary toilets, most of which have a tank for accommodating raw sewage therein. However, the temporary toilet has a problem in that the raw sewage stored in the tank is sucked into a vacuum truck for collection, which is laborious and time consuming.
Transportation vehicles such as trains, buses, vessels, etc. which operate over long distances are provided with an exclusive tank for storing and holding the discharged raw sewage. The raw sewage in this tank is subjected to a deodorizing treatment by chemicals, and thereafter collected by a vacuum truck.
In facilities of the above type, the raw sewage is stored in the state as discharged from the human body, so that disposal of the raw sewage is unhygienic. Also, a long period of use of the tank creates sewage residue on the tank which causes a bad smell which is disliked by an operator. Thus, such temporary sewage facilities are not preferable in modern times.
In an attempt to improve on the above, there have been proposed several hygienic proposal methods. In one method, for example, chemicals are introduced into the tank where the raw sewage is stored to thereby prevent the bad smell and effect a sterilization. This is mainly employed in the transportation industry such as on trains. This method, however, cannot be used for a long period of time because the chemicals become diluted, and costs are high.
In another method the raw sewage is stored in a bag made of vinyl to prevent the diffusion of the bad smell. This method however requires a vinyl bag of large size and involves high cost for disposal thereof, and is troublesome in separating the raw sewage from the bag.
In still another method the discharged raw sewage is directly dried by use of heat from a burner, etc. Since the primary component of raw sewage is liquid, it requires a large amount of heat energy to remove the liquid and it takes a long time to effect disposal of the raw sewage.